Common rail fuel systems utilize a common rail maintained at an injection pressure to supply fuel to a plurality of fuel injectors. In many instances, pressure in the common rail is controlled by controlling output from a high pressure pump. In the event of a system fault, such as a failed fuel injector, pressure in the common rail can surge and exceed system design pressures. In order to prevent the common rail system from becoming over pressurized, the industry has taught the use of a pressure relief valve that opens to relieve pressure in the common rail at some valve opening pressure that is substantially higher than normal operating injection pressures. U.S. Pat. No. 8,240,291 and United States Patent Application Publication No. 2006/0196476 show examples of pressure relief valves for use in common rail fuel systems. In the event that the valve develops a leak or some other problem such as opening at a lower pressure than its design valve opening pressure, effective operation of the common rail fuel system can be substantially undermined.
The present disclosure is directed toward one or more of the problems set forth above.